Modelling and analysing Safety Acceptance Decision Making Processes in the MoD

摘要

Procurement of safety-critical and safety-related systems is a complex process involving both technical and social acceptance processes. There are a number of modelling techniques that can be used to analyse system failures - such as Systems Theoretic Accident Modelling and Processes (STAMP), responsibility modelling, and Human Factors Analysis and Classification System (HFACS). This paper undertakes a retrospective analysis of a major Ministry of Defence (MoD) aircraft accident using two techniques to try and identify the system failures associated with the procurement of software. This is undertaken via application of two differing techniques and an analysis of the results obtained. The analysis highlights many potential system failures across a diverse set of groupings including skill based, financial/resource based and process based failures. The analysis demonstrates that the techniques have particular strengths but also that they do not cover all potential issues. Finally, the paper proposes that there are more important lessons to be learned - such as the socio-technical issues surrounding the decision making processes. The use of such models could be extended to include the determination and analysis of safety acceptance decision processes thus identifying where confidence is required to support the decision making process prior to it being necessary.